This application seeks continuation of support for a successful program whose objective is to recruit and train well- qualified predoctoral students in mechanisms of microbial pathogenesis. The program emphasizes both the microbial and host sides of pathogenesis since the two, and their interplay, are so intimately connected in causing disease. This training grant, by bringing together the best infectious disease-related researchers in San Antonio, will offer the students a wide choice in dissertation projects; >20 different viral, bacterial and eukaryotic pathogens with importance in infectious diseases and bio-defense are being investigated in the preceptor labs as are the corresponding ranges of host defense responses/components in innate and adaptive immunity. The 16 preceptors participating in this application come from the University of Texas Health Science Center at San Antonio (UTHSCSA with 11 preceptors from 4 different departments), the University of Texas at San Antonio (UT, 4), and the Southwest Foundation for Biomedical Research (SFBR, 1). All of the mentors have strong graduate training records and extramural research grants. One strength of this application is the collaborations that have already been established among the participating faculty from different campuses, which has not only facilitated the investigation into the mechanisms of microbial interactions with hosts and the application of the knowledge on the interplay of both sides of pathogenesis to vaccine development, but, more importantly for this grant, has provided and will continue to provide multidisciplinary training opportunities for the students. All of the preceptor laboratories are appropriately equipped to perform cutting edge research and the various participating institutions support many different core facilities including multiple BSL-3 areas and one BSL-4 facility. During the previous ten years, this training program has provided critical support for 20 students, many of whom are now making significant contributions to infectious disease research as independent investigators in academia and industry. With the recent implementation of the Integrated Multidisciplinary Graduate Program at UTHSCSA, the Microbiology & Immunology (MI) Track has been able to attract more qualified candidates. Importantly, the MI Track has made, and will continue to make, a commitment to the recruitment and training of minority and women students. In the past three years, -50% of our U.S. applicants were minority students and 56% were female students. Because South Texas is one of the fastest growing areas of the country, the Training Grant preceptors are keenly aware of the opportunities for recruiting minority students and are eager to participate in their training for the benefit of this region and the US. Given the strength of our training program and the opportunity for and commitment to training minorities, we are requesting a continued support for the training of three predoctoral students for the next five years. RELEVANCE (See instructions): This training grant consists of 16 preceptors working on >20 different viral, bacterial and eukaryotic pathogens with importance in infectious diseases and bio-defense and a wide range of host defense responses/components. It will continue to provide the opportunities for the youngsters including those from minority and disadvantaged families who are inspired to pursue a life science career to realize their dreams. This training grant-supported effort will help supply the nation with top quality researchers in combating infectious diseases.